Bangladesh's opposition has called a new 48-hour general strike to protest at the killing of its supporters by police during a violence-plagued general election.

The Bangladesh Nationalist Party (BNP) said the shutdown would begin on Monday morning, effectively extending a protest which was in place throughout the weekend as part of a campaign to wreck Sunday's election.

"We've called the strike to demand that the government declares this farcical election null and void," BNP spokesman Sayrul Kabir told AFP.

"We are also protesting the deaths of 22 of our supporters in police firing during today's vote," Kabir added.

Police say at least 15 people were killed in violence during the voting, most of them opposition activists who were shot dead as they tried to disrupt the poll.

A polling officer and a security guard were also beaten to death by opposition protesters, according to the police.

The BNP and 20 other parties boycotted the election after Prime Minister Sheikh Hasina spurned their demands for the polls to be overseen by a neutral caretaker government.

Hasina's Awami League is guaranteed victory as its members or allies faced a clear run in 153 of the 300 constituencies.

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